Summary
On October 17, 2012, at about 1119 local time (0649 UTC), a Bombardier DHC-8-315 registration N800AW, operated by the United States Department of State, landed hard on runway 29 at Kabul International Airport (OAKB) in Kabul, Afghanistan. The three passengers and three crewmembers on board were uninjured, but the aircraft sustained substantial damage. Visual meteorological conditions were reported at the time. The flight had originated from Tarin Kowt Airport (OATN) in Tarin Kowt, Afghanistan.
Flight Details
According to the flight crew, the takeoff, climb, and cruise phases were uneventful. The captain was the pilot flying. At 11:12, the flight received clearance for the approach. At 11:16, the crew selected flaps 35 and began a random steep approach as per company task procedures, due to the airport threat level. The crew stated that engine power was reduced to idle for the approach and was not increased before landing. Flight Data Recorder (FDR) data showed that engine torque was at or near zero for the last five minutes of approach and landing.
Conditions
The aviation routine weather report at 0550 local time indicated wind from 120 degrees at 5 knots, visibility 8000 meters, and temperature 17°C. In the two minutes before landing, wind was light and variable. A tactical meteorological observation system recorded wind direction variable from 004° to 137° and speed variable from 1 knot to 7.2 knots. Wind gusts during that period varied from 050° to 079° at 7.0 to 7.2 knots.
Findings
Based on FDR data, the calculated rate of descent was about 2,000 feet per minute during the approach, reducing to about 1,500 feet per minute just before landing. The airplane touched down with a nose-up pitch attitude of approximately 8 degrees and a peak vertical acceleration of 2.7g. According to the manufacturer, the aft fuselage would contact the runway at a pitch attitude over 11.9 degrees with an extended landing gear oleo strut, or over 6.8 degrees with a compressed oleo strut. To avoid nuisance warnings from the steep approach, the flight crew had deactivated the ground proximity warning system (GPWS). The source noted that such alerts would be expected during this type of approach, making it unlikely that they would have prompted corrective action. Upon touchdown, the aft fuselage contacted the runway, resulting in substantial damage including buckled, cracked, and bent frames and stringers.